How to install a Heavy Duty 4 disc TA. Checking the end play

Posted by
Joe Schmitt
on January 27, 2017

This writing deals with checking the end play on IH hydraulic Torque Amplifiers with the heavy duty 4 direct drive clutch plates. This is important because the original design 3 disc direct drive TA's had a lot more room on the quill shaft, so end play was not a factor. The 4th disc on the heavy duty versions rides on the end of the quill gear which makes full use of the quill gear. However if there is too much end play the 4th disc has the potential of falling off the end of the quill gear.

These instructions begin withe the center clutch housing removed from the tractor and the speed transmission and TA assembly removed and ready to install the reman heavy duty TA assembly.

These instructions are not included in any of the original service manuals because when they were written the heavy duty 4 disc TA was not developed.

This is just my way of doing this procedure and has worked well for me. You may have another way to achieve the same results.

1st install the new bearings in the quill gear/shaft to
the correct depths 9/32" from the large end and 1 1/32" from the
small end. 2nd install the new quill in the quill housing. 3rd
position the new TA so that the rear end of the TA is facing up (
be sure to leave the hose clamp on the front input shaft). With
the rear of the TA facing up use the old quill gear to align the 4
clutch plate splines so the quill slides down into all 4 discs.
The quill should rotate smoothly make sure all 4 discs appear to
be lined up. Work the old quill down into them a couple times to
make sure it is into the last one. Then install the new one that
is in the quill housing making sure it is into the 4th disc. Now
use a 2 3/4" or 3" x5/16" course thread bolt and a stack of
washers to hold the quill and quill housing into the back of the
TA. There are 3 holes in the end shaft of the TA ,thread the bolt
and with washers into the shaft into one of the 3 tapped holes so
that the quill is held down through all 4 discs.

Prepare the housing , install the 3 jumper tubes into the
housing with new orings and pull them out to the inside oring so
they don't interfere with the TA installation. Stand the housing
up on the rear surface( bell end or front facing up). Clean the
front TA mounting surface and the rear quill housing mounting
surface.

Now attach a 3/8" course thread lifting eye bolt into the front
input shaft of the TA assembly after it is inverted so the front
shaft is access able. Then hang the TA assembly with the quill
housing bolted in with the 3" bolt and washers on a hoist with
about a 3ft chain.

Using the hoist lower the unit into the
housing pushing or pulling on the chain to align the unit to drop
into the housing straight. ( do not install the large oring on the
front of the assembly at this time). Lower the assembly
completely , it should be hanging by the front flange of the TA.
. Now check to see that the quill housing can rotate freely. If
it does not you need to remove the unit. If it does, rotate freely install the
bolts into the front TA flange and tighten them slowly making sure
that the quill housing is still able to rotate freely. If it does
after the bolts on the front are tight, then you can proceed.

I turn the housing now so that the rear surface is facing up and
the front is down. ( I have the housing mounted on a engine style
stand for easy rotation). With the rear of the housing facing up
remove the 3" bolt and washers from the quill and thread the 4
bolts into the quill housing but do not draw them down just start
the threads. Next set up a dial indicator gauge with the pointer
on the rear or up facing large quill gear surface and zero the
dial indicator. Now draw the bolts down while watching the dial
indicator. With the bolts tight the dial indicator should read
between .005" and .025". This is the correct end play. If the end
play is more than .025" you will need to install a paper shim that
is included with the TA assembly to achieve the correct end play. If you have less than .005" of end play you will need to call me 715-495-4932. Provided you bought the TA assembly from me I can explain to you how to correct the problem. If not you are on your own. Once you determine that the ens play is between .005" and .025" you can proceed.

Now remove the 4 bolts and reinstall the 3 " bolt with washers so
you can remove the unit to install the large oring on the front of
the TA. After the unit end play is set correctly and the large
oring is installed and the unit is completely bolted in you can
remove the hose clamp from the front input shaft and proceed with
the remaining assembly.